Field of the Invention
The present invention relates to an imprint apparatus, a foreign particle removal method, and a method of manufacturing an article.
Description of the Related Art
The imprint technique can form a nanoscale fine pattern, and is coming into practical use as one of lithography techniques for volume production of magnetic storage media and semiconductor devices. An imprint apparatus which employs the imprint technique forms a pattern on a substrate such as a silicon wafer or a glass plate using a mold (die), as an original, on which a fine pattern (unevenness) has been formed. The imprint apparatus, for example, applies a light curable resin (for example, an ultraviolet-curing resin) on the substrate, and molds the resin using the mold. The resin is irradiated with light (for example, ultraviolet light) to be cured, and then the mold is separated from the cured resin, thereby forming the pattern of the resin on the substrate.
In the imprint apparatus, since the mold and (a resin on the) substrate are brought into direct contact with each other, if a foreign particle is present in a process space, a defect (transfer error) occurs in the pattern to be formed on the substrate, or the mold is damaged.
Japanese Patent Laid-Open Nos. 2010-176080 and 8-181096 propose techniques of removing foreign particles present on a substrate. Japanese Patent Laid-Open No. 2010-176080 discloses an arrangement of providing a suction mechanism which suctions a space on the substrate to remove the foreign particles present on the substrate. On the other hand, Japanese Patent Laid-Open No. 8-181096 discloses an arrangement of providing, in addition to the suction mechanism which suctions the space on the substrate, a blowing mechanism which blows a fluid (gas) onto the substrate to separate the foreign particles from the substrate easily.
In the conventional technique, however, the foreign particles separated from the substrate may adhere on the substrate or a substrate chuck again. Thus, the conventional technique is inadequate for a technique of removing foreign particles present in a process space. Especially in Japanese Patent Laid-Open No. 8-181096, the fluid is blown onto the substrate, resulting in scattering the foreign particles separated from the substrate in the process space.
In the imprint apparatus, the foreign particles tend to stay in a gap between the substrate chuck holding the substrate and a protective plate (flush plate) surrounding the substrate chuck. Since size reduction of the imprint apparatus is intended by restricting the movable range of the substrate stage, the degrees of freedom in the arrangement of the suction mechanism and the blowing mechanism in the apparatus are low. The conventional technique therefore cannot efficiently remove the foreign particles present in the gap between the substrate chuck and the protective plate.